Effects of post weld enhanced-solution on the microstructures and mechanical properties of 2519A aluminum alloy welded joints

摘要

The effects of enhanced-solution plus aging treatment on the microstructures and mechanical properties of 2519A aluminum alloy welded joints were investigated by optical microscope, mechanical test, scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that the heat-affected zone(HAZ) is a soft zone due to over-aging caused by heat input during welding. After enhanced-solution plus aging treatment, the soft zone disappears, and fine strengthened precipitates emerge in weld zone and HAZ. The 4h→535°C/2.5h enhanced-solution can increase the final solution temperature without the formation of overheated microstructure, and improve the solution of second phase, then more fine strengthened precipitates can be attained during aging treatment, so the hardness and tensile properties of the welded joints can be further increased.